HP z27x Review
by Chris Heinonen on December 2, 2014 4:00 PM ESTSurprisingly the HP z27x does not fare well on our uniformity testing. With most professional displays, having good uniformity is important because of their target market. This makes the performance that we see from the HP z27x all the stranger.
White Uniformity sees a lot of light drop-off at the edges of the screen. A very good display will only drop down 10% to 180 cd/m2 or so but the HP falls all the way to 153 cd/m2 in one zone. This fall-off of almost 25% is much higher than would be expected, and is something you can see when you have a uniform field up on the screen.
Black Uniformity is similar, with those same zones on the display having a lot of light fall-off leading to darker blacks. Having darker blacks is always good, but these are dark because of uneven backlighting which is not something we want to see of course.
The contrast uniformity shows that these backlighting issues are pretty consistent. There is some variation in the contrast ratio, but the minimum level is 900:1 and it goes up to 1,047:1 in one zone. This is better than we measured with the APL patterns (uniformity uses full-field) and everywhere on the display has a good contrast ratio. The contrast uniformity measures very well on the HP z27x.
The biggest issue is the color uniformity. This is probably tied back into the white uniformity, as the luminance level being incorrect will cause the colors to be incorrect. One zone, the very dim one, has an average dE2000 of almost 6.0 compared to the center. This poor backlighting causes the colors to all appear off compared to what is in the center. The panel itself might be uniform but if the backlight is not, what you see on the screen will not match up.
Overall the uniformity measurements of the HP z27x surprise me. I expected much better results from the monitor because of its target market. The panel might calibrate to be very accurate, but what you see in the center of the screen is not going to match up to what you see on the edges of it.
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SanX - Sunday, December 7, 2014 - link
The author has done absolutely right things. HP indeed does not care even to cherrypick. HPs and Dells became more and more a rebranders of Chinese goods. And actually it is not the China the final reason in bad quality control of everything but WE THE BRAINDEAD PEOPLE and of course our croocky american sales/middlemen who exploit this vulnerability of average technically illiterate Joe and are just interested to drop more larger margin shiny crap on the heads of dumb public, on our heads.DanNeely - Tuesday, December 2, 2014 - link
It might've been the 1st time it crossed your desk; but NEC's offered in monitor calibration since (at least) the the Multysync 3090 (released around 2008). I'm not sure how it compares with HP's offering; but they've got something called NaViSet to allow centralized admin of display settings. Lastly, IIRC their internal calibration does have some ability to adjust for uneven backlighting (presumably at the cost of some overall contrast).http://www.necdisplay.com/support-and-services/nav...
cheinonen - Wednesday, December 3, 2014 - link
I've used and reviewed the NEC PA series, and while they offer an internal LUT with calibration options, it has to be done through the SpectraView II software. The HP allows you to do it entirely inside the display without a PC at all, making it easier to do a large number of them. The NEC PA series also lacks the Ethernet control. The uniformity on the NECs is top notch.baii9 - Tuesday, December 2, 2014 - link
Wide gamut -> GB-r LED -> uniformity issue, why am I not surprised.Here is when good warranty kick in, panel lottery.
Doomtomb - Tuesday, December 2, 2014 - link
This monitor came out in 2014? This looks like something that would've come out in 2009. The bezel is huge. The body is thick. The resolution is nothing special. I don't care if it has features, and the color gamut. Seriously, this is the mind of the average consumer.D. Lister - Tuesday, December 2, 2014 - link
This product isn't targeted at the average consumer.DanNeely - Wednesday, December 3, 2014 - link
Although one of the reasons why pro-grade monitors tend to be significantly thicker than consumer ones is to put an array of evenly spaced backlights behind the panel instead of just a few on one or more edges using mirrors to bounce it around; because the former results in more even illumination.Something that clearly didn't happen with this monitor; and since AT has proven willing to hold reviews if they see unexpectedly bad results and the vendor says "looks like something broke, let us send you a replacement to test" or "we didn't test that case and need to write a new firmware to fix the problem" I can only assume that HP considers the level of backlight variation Chris saw in this model acceptable.
kyuu - Thursday, December 4, 2014 - link
Based on Chris's own statement in these comments, your assumption would be wrong. It seems that Chris didn't inform HP or offer them the chance to send a replacement in order to avoid the appearance of receiving a "cherry picked" sample.... Seems kinda silly to me. Unless Chris purchased the review unit himself, HP already had the chance to submit a cherry picked sample. Giving them the chance to fix what may very well be damage incurred during shipping does not somehow break reviewer ethics.
baii9 - Wednesday, December 3, 2014 - link
average consumer don't drop 1.4k on a 27" monitor.jann5s - Wednesday, December 3, 2014 - link
The ASUS MX229Q is using more power at minimum then at maximum, I guess there is a booboo in the database (LCD Power Draw figure)